/ ˈekspɜːt; NAmE -pɜːrt/ noun , adjective
■ noun
expert (at / in / on sth) | expert (at / in / on doing sth) a person with special knowledge, skill or training in sth :
a computer / medical expert
an expert in child psychology
an expert on modern literature
He's an expert at getting his own way.
Don't ask me—I'm no expert!
■ adjective
expert (at / in sth) | expert (at / in doing sth) done with, having or involving great knowledge or skill :
to seek expert advice / an expert opinion
an expert driver
We need some expert help.
She's expert at making cheap but stylish clothes.
They are all expert in this field.
—compare inexpert
► ex·pert·ly adverb :
The roads were icy but she stopped the car expertly.
The music was expertly performed.
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WORD ORIGIN
Middle English (as an adjective): from French , from Latin expertus , past participle of experiri try. The noun use dates from the early 19th cent. Compare with experience and experiment .